In the information searching field, traditional keyword-based information retrieval methods have limitations. The same word can have different meanings in different contexts. For example, the word “apple” has very different meanings in different fields. The word “apple” expresses a type of fruit and also expresses a brand of electronic products. If a user intends to search a type of fruit and enters “apple” into a search engine as the keyword, the returned search results will generally include information concerning the two vastly different subjects of fruit and electronic products. In this case, information relating to the brand of electronic products does not match the user's search intentions. Accordingly, keyword-based information retrieval methods may return divergent results between the search results and the user's search intentions.
Technologies exist to address the divergent results of corresponding images for most of the data information that is online. On some search systems, for example, when a user performs an information search, the user can enter an image into the search engine. Thus, based on the image entered into the search engine by the user, by retrieving all information related to the image (hereinafter referred to as the image information), images that have image information matching the entered image information can be retrieved from the image library. By matching the entered image information to image information in the image library, the disadvantages of the keyword-based information retrieval methods described above can be overcome.
Similar to the generation of an information index in the keyword-based information retrieval methods, the image-based information retrieval method described above also generates an index for the large amount of images in the image library, to provide data support for the subsequent retrieval method. When an image index is generated for the images in an image library, conventional image-based information retrieval technologies use file names relating to the images (or other text information relating to the images). Preconditions for the method to be used include users manually adding descriptive text information to the images. One of the limitations of an image index generation method including the manual addition of descriptive text information is the fact that the number of images in an image library is usually very large. Thus, the conventional image index generation method including the manual addition of descriptive text information results in a large consumption of processing resources. Furthermore, because a user's subjective feelings about the images are incorporated into the descriptive text information, the image index generation methods described above may have reduced accuracy due to the influence from the user's subjective feelings.